I am new at this. I have a 30 litre tank which is 8 weeks down the line from starting it off. I have 5 guppies who appear to be doing ok. I bought one guppy every week. I have stopped now. I get my water checked weekly at Pets at home. For the last two weeks my nitrite levels are quite high. I am sorry I do not know the figure but it was quite purple the reading. There is no amonia though. The guy at the shop said its just cycling and to do 10 % water changes daily. I wanted to check to see if this is the best advice. How long will it take before I see the nitrite going down. I was told it would take 6 weeks.